Question

An object of height 12cm is placed in front of a convex mirror of focal
length 20 cm. Calculate the distance of the object from the convex mirror
so that an image is formed 15 cm behind the mirror .Also find the size
of the image formed.
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Answer 1

Answer:

Parallel rays of light that are also parallel to the main axis gather (converge) at the focal point of a concave mirror. It is for this reason that a concave mirror is also called " converging mirror". Distance VF = f is called the focal length. It can be shown that f is 1/2 of R, the radius of the mirror.

Answer 2

Answer:

u= 12cm

f =-20

hi=15

Now u put the formula

1/f=1/v+1/u

m=hi/ho